Quote Originally Posted by larrysb View Post
But the inline 6 provides a much smoother engine. The inline 6 is intrinsically balanced. The V6 on the other hand, is a shaky jake, and needs stuff like balance shafts to get it reasonably smooth enough for a luxury car.

So there is a technical reason for the straight 6.
I agree, my supercharged BMW M Roadster is very smooth.